首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A method for recovering dermatoglyphic data from tamarin cadavers is described. The method involves the complete removal of the palmar and plantar pads with no destruction to the underlying skeletal elements. Once recovered, the pads are stored in a formalin solution. The stored pads of 213 individuals have remained in a good state of preservation for dermatoglyphic analysis for over four years.  相似文献   

2.
In dermatoglyphic methodology the system of gross classification of digital pattern types needs modifications. More attention should be focussed on the study of minute morphological variations among pattern types in order to understand fully the genetic mechanisms involved in pattern variations. A systematic classification to record many of the morphological peculiarities is lacking. This paper proposes a classification and methods of identification of the direction of the course of the ridges inside the pattern area of true whorls. In all, nine ridge course types are identified, named and described. Data analysed on the basis of the above methods and classification reveal significant bilateral differences for clockwise and counter-clockwise types of ridge directions. Mode of inheritance, bisexual differences, etc., of the polymorphic course of these ridges should be studied. Its usefulness in the field of personal identification, population genetics and medicine should also be evaluated.  相似文献   

3.
4.
A population sample from the Milne Bay district of Papua-New Guinea was found to have extremely high pattern intensity indices and total ridge-counts. These fell into the range of certain Australian Aboriginal tribes, and so argue for a possible connection between this region of Melanesia and the Australian Aborigines, although equally strong connections with other regions of Melanesia are known.  相似文献   

5.
The blastoderm of the avian embryo acts during the early stages of development as an integrative system programmed to form a single embryonic axis. Isolated parts of the blastoderm are known to each form an axis, owing to the system's properties. In the work reported here, the regulative capability of the right and left halves of chick blastoderms to form an embryonic axis was examined systematically at different stages. This revealed a progressive change in the developing blastoderm. After early separation, the axis in each half will form at some distance from the blastoderm's original midline, while with late separation the axis will form next to the original midline and may even lack one row of somites at the medial rim. Since development stops in culture after about 2 days, axis development after early separation ceases before somites are formed, whereas after late separation somites and brain vesicles can develop. In addition, an attempt was made to learn whether the two halves of blastoderm, when shifted along the midline and then reunited in staggered fashion, act as a single or two separate embryonic fields. When reunion of the right and left halves was achieved so that the posterior end of one half was adjoining the posterior area pellucida region of the other half, a single embryonic axis developed. When, on the other hand, the shift was larger so that the posterior end was fused to the central area pellucida of the other half, two separated embryonic axes developed.  相似文献   

6.
The quantitative dermatoglyphic traits of the Taimir aborigines have been studied in this paper. The correlation matrix of the traits was analyzed by a nonmetric two-dimensional scaling method and by a principal components method. Comparative contribution of palmar and digital traits variation to the principal components is under discussion.  相似文献   

7.
Accessory triradii and the atd angle were examined via complex segregation analysis in order to evaluate possible genetic effects on these dermatoglyphic traits, measured in an endogamous Brahmin caste of peninsular India. The phenotypes considered included: presence of accessory palmar triradii a' and d', associated with the interdigital areas II and IV, respectively; presence of an accessory axial triradius tt' associated with the proximal margin of the palm; and an arctanh-transformation of the atd angle measurement. For all accessory triradii considered in the present investigation familial resemblance was evident. The most parsimonious model which could account for the observed resemblance was a multifactorial model that includes polygenic effects as well as transmissible environmental effects that are inherited in the same pattern as polygenes. Evidence of familial resemblance was also found for the arctanh-transformed atd angle, which could be attributed, initially, to both a major effect and a multifactorial component. Tests of transmission of a putative major gene were performed which yielded results consistent with Mendelian transmission, although an alternative test of no transmission of the major effect also fit the data. In light of these contrasting results we are precluded from accepting with confidence the notion of a major gene influence on the atd angle. We have concluded that the accessory triradii a', d', and tt', and the atd angle are influenced by multifactorial effects, including additive polygenes and possible environmental factors, such as intrauterine effects.  相似文献   

8.
We determined the ridge-counts and their correlations of interdigital area a-b, b-c, and c-d among 300 boys and 300 girls from Jena and 95 male and 79 female cerebrally damaged chidren from the Mental Hospital of Stadroda, both in Thuringia, G.D.R. (East Germany). The mean values of the normals and the patients differ significantly only on the right hand of males in the b-c area (p ≤ 5%). Bimanuar comparisons showed significant correlations in the three areas in both sexes in the normal and the abnormal children. Inter-area comparisons revealed no significant correlation between a-b and b-c areas; correlations were significant between a-b and c-d areas in both sexes in the normal group, but significant for the right hand only in cerebrally damaged children. Highly significant correlation was found between the b-c and c-d areas only in the right hand of female cerebrally damaged children. Comparative data from Bavaria and North-Rhine-Westfalia are also presented.  相似文献   

9.
人类指掌皮肤嵴纹与智力发育的相关性研究   总被引:5,自引:1,他引:5  
本工作对120例遗传型智残者和60例非遗传型智残者的指、掌皮肤嵴纹数进行分析,并分别与相同例数的对照组同类资料进行比较,找出与智力发育相关的指端、指间区、指基部皮纹参数,据此将遗传型智残组按智商值的不同分为6个组,将不同智商组对应的各区嵴纹数进行分析处理。结果表明,指端皮肤嵴纹数与智商呈正相关,相关系数r=0.8319,各指间区和指基部嵴纹数与智商值呈负相关,相关系数r=-0.7392。 Abstract Digital and palmar of 120 cases of hereditary mental deficiency and 60 cases of non-hereditary mental deficiency were analysed, and compared with the control group using the same cases and identical data, and then skin vein parameter interrelated with intelligence development for digital end, interdigital area, digital root were found. In the light of this we divided the hereditary mental deficiency group into 6 accorcding to IQ value, and analysed statistically every area ridge count corresponding to different IQ group. The result showed that ridge count of digital end was positively correlated with IQ value correlative coefficientr=0.8319; Whereas ridge count of interdigital area and digital root were negatively correlated with IQ value correlative cofficientr=0.7392.  相似文献   

10.
11.
12.
In order to test the hypothesis of a major gene effect on absolute total finger ridge count (ATFRC), the nature of relationship between mean ATFRC and its variability was evaluated in a series of 47 population samples from India. Regression analysis showed that both the standard deviation and the coefficient of variation are significantly related to mean ATFRC, and about 35% of the variation in ATFRC is explained by the dependent variable coefficent of variation. These results support the hypothesis of a major gene effect on the trait ATFRC.  相似文献   

13.
The idea has been generally accepted that accumulative properties of the lower atmosphere during stable non-turbulent air conditions by night (inversion) would lead to relatively high concentrations of airborne particles including those of biological origin like pollen grains originating from wind pollinating plants. Using temperature gradient, air pollution potential, and urban grass-pollen counts as criteria in a meteorologically homogenous region in the western part of the Netherlands, this relation between inversion and airborne grass-pollen concentration appears to be very weak and of no significance for the causation of nightly peaks in the grass-pollen counts.  相似文献   

14.
Essential oil yield and composition in seven natural populations of Lavandula latifolia from the eastern Iberian Peninsula were determined by GC/MS. Twenty-eight constituents were identified, accounting for 92.0–95.4% of the total oils. These oils were dominated by the monoterpene fraction and three of them (linalool, cineole and camphor) constituted 79.5–86.9% of the oil from flowers. Essential oil yield in leaves and flowers varied among and within populations, but hierarchic analyses of variance showed that the proportion of variation attributable to individuals was significantly higher than that attributable to population differences. Principal component and cluster analyses allowed three groups of flower essential oils to be distinguished according to their high, intermediate and low proportion of linalool. These essential oil types are respectively correlated to the Supra-, Meso- and Thermo-Mediterranean bioclimatic belts where the populations are located. A genetic analysis based on those terpenes that showed a trimodal distribution roughly corroborated the relationships between the seven populations obtained from the ordination analyses and emphasizes the distinctiveness of some of the populations.  相似文献   

15.
Lipid-metabolizing enzymes of myelin and their relation to the axon   总被引:9,自引:0,他引:9  
The old concept of myelin as a metabolically inert membrane has been considerably revised as a result of the discovery of numerous enzyme activities in the isolated membrane. The high degree of purification and low levels of contamination markers leave little doubt that the measured activities are intrinsic to myelin itself. Slightly more than half of the discovered activities involve lipid metabolism. One such enzyme, neutral cholesterol esterase, is myelin-specific, while the rest occur in other subcellular fractions as well as myelin. These include activities involved in synthesis of cerebrosides, phospholipids, and cholesteryl esters; only a few degradative enzymes are presently known. In vivo studies have shown that various substrates utilized by lipid-synthesizing enzymes of myelin can originate in the axon. Six such substrates have been characterized. The possibility exists that these enzymes may be wholly or partially dependent on the axon as the primary source of substrate, thereby suggesting a possible form of metabolic dependency of myelin on the axon.  相似文献   

16.
17.
Summary The apparent dissociation constants of the complexes of AMP with the methyl esters of amino acids in aqueous solution exhibit good correlations with features of the genetic code and with the frequencies of occurrence of amino acid residues in proteins. Thus it is likely that chemically selective nucleotide-amino acid interactions were involved in the processes of chemical evolution that have led to the emergence of the genetic code. Based on these correlations a storage device for the information regarding nucleotide-amino acid interactions is proposed. It involves processes of simultaneous polymerization to polynucleotides and polypeptides.  相似文献   

18.
Astroctyes express a set of three connexins (Cx26, Cx30, and Cx43) that are contained in astrocyte-to-astrocyte (A/A) gap junctions; oligodendrocytes express a different set of three connexins (Cx29, Cx32, and Cx47) that are contained in the oligodendrocyte side of necessarily heterotypic astrocyte-to-oligodendrocyte (A/O) gap junctions, and there is little ultrastructural evidence for gap junction formation between individual oligodendrocytes. In addition, primarily Cx29 and Cx32 are contained deeper in myelin sheaths, where they form autologous gap junctions at sites of uncompacted myelin. The presence of six connexins in macroglial cell populations has revealed unprecedented complexity of potential connexin coupling partners, and with restricted deployment of gap junctional intercellular communication (GJIC) within the "pan-glial" syncytium. New implications for the organization and regulation of spatial buffering mediated by glial GJIC are derived from recent observations of the existence of separate astrocyte anatomical domains, with only narrow regions of overlap between astrocyte processes at domain borders. Thus, widespread spatial buffering in the CNS may occur not successively through a multitude of processes arising from different astrocytes, but rather in a more orderly fashion from one astrocyte domain to another via intercellular coupling that occurs only at restricted regions of overlap between astrocyte domains, augmented by autocellular coupling that occurs within each domain.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号